1. Field of the Invention
The present invention relates to lasers and particularly to a flashpumped solid state laser which operates at a wavelength of 1.96 microns at or near room temperature.
2. Description of the Prior Art
Development of room temperature solid state lasers in the two micron spectral range has received renewed attention recently because of potential applications in medicine and optical communications.
Two important criteria which determine the effectiveness of a laser source in medical applications include the absorption coefficient of the tissue specimen at the operating wavelength, and the availability of a suitable fiber optic delivery system. In the near infrared wavelength region, laser ablation is most effective at 1.93 microns and 2.94 microns, which correspond to tissue absorption peaks. In addition to operating near an absorption peak of tissue, it is also important to consider the availability of a suitable fiber optic delivery system at the output wavelength of the laser system. With regard to transmission, flexibility, durability, and nontoxicity, the best optical fibers for medical applications are silica based fibers. These fibers have demonstrated excellent performance in the wavelength region between 0.3 microns and 2.1 microns.
Several flashpumped and laser (including diode lasers) pumped solid state lasers have recently been demonstrated to operate in the 2 micron region at room temperature. To date, all of the medical studies with these lasers have employed wavelengths longer than 2 microns. However, it has been shown that the peak absorption of water, and therefore of tissue, is in the spectral region between 1.90 microns and 1.98 microns.